1. Field of the Invention
An aspect of the present invention relates to a driving machine for driving fasteners, such as nails, tacks and staples, into members to be fastened.
2. Description of the Related Art
A portable driving machine is known in which connected fasteners loaded in a magazine are driven from the tip end of a driver guide sequentially one by one using a drive source (power source), such as a pneumatic type in which compressed air is supplied from an air compressor to the main body of the driving machine and the pressure of the air is used; a gas combustion type in which a small gas cylinder is mounted on the main body of the driving machine and the gas stored in the gas cylinder is combusted; or an electric motor type in which a storage battery and an electric motor are mounted on the main body of the driving machine and the drive power of the electric motor is used. In this kind of driving machine, a mechanism having a contact arm extending from the vicinity of the tip end section of the driver guide to the vicinity of the trigger section of the driving machine is generally adopted. With this mechanism, only in the case that the tip end of the contact arm is pushed against a fastened member, such as wood, the other end of the contact arm is retracted upward and engaged with the trigger mechanism, and the operation of the trigger is enabled for the first time. Hence a fastener can be launched and driven into the fastened member by next carrying out the pulling operation of the trigger.
For example, as disclosed in JP-2005-7547-A described above, a mechanism is provided in which in the case that the contact arm thereof is urged toward its top dead center at all times in its initial state and that the tip end section of the contact arm at the tip end of the launching section is not made contact with a fastened member, even if the pulling operation of the trigger is performed, the contact arm is only moved downward and the launching drive section cannot be started. Since the tip end section of the contact arm is not required to be strongly pushed against the fastened member, this technology is advantageous in that the finish and workability of the fastened member are excellent and that the driving efficiency and operability of the driving machine can be improved.